￼ Although the Arduino Yún requires no specific procedure, the Ethernet or WiFi network needs to be installed and configured successfully before any upload, and the RSA key fingerprint of the Arduino Yún needs to be known by the Mac.

Check that the router has discovered the Arduino Yún and note the IP address.

Check the Mac knows the RSA key fingerprint of the Arduino Yún.

Also, keep the password of the Arduino Yún at hand.

Disconnect all the SPI devices from the ICSP connector as the WiFi module uses SPI to communicate with the Arduino.

It is recommended to proceed with a test of the over-the-air upload with the Arduino IDE, through Ethernet or WiFi, to be sure that the Mac recognises the board and knows the RSA key fingerprint of the Arduino Yún.

The Arduino Yún board should appear as arduino.local but often has a different name, as host-001.

The default address should be 192.168.240.1 but may differ according to the settings of the network.

To check the Mac knows the RSA key fingerprint of the board,

Open a Terminal window and type the command ssh root@ followed by the IP address of the board, 192.168.240.1 in the example.

$ ssh root@192.168.240.1

If the board is unknown, a message asks for confirmation of the RSA key fingerprint.

The authenticity of host '192.168.240.1 (192.168.240.1)' can't be established.
RSA key fingerprint is 00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff.
Are you sure you want to continue connecting (yes/no)? yes

Enter yes and validate.

A message confirms the RSA key fingerprint has been added to the list of know hosts.

There are three requirements. First, upload is done through Ethernet or WiFi connection. Second, the project has a folder named www with at least a file named index.html. Third, the Arduino Yún has a microSD-card inserted on the slot.

During upload, the content of the www folder is copied to the microSD-card automatically and made available with a browser at the address /sd/TemperatureWebPanel.

Once upload is completed, embedXcode open the browser at the website main page.